Yes, it is often considered a weed in gardens, though it is also a valued food source.

It is typically boiled or stir fried like spinach.

Plant guide

Slender amaranth.

Amaranthus viridis

Pronounced am-uh-RAN-thus VIR-ih-diss

Also known as Callaloo, Green amaranth, Wild amaranth, Slender Amaranth

This plant is a common annual herb often found in disturbed soils and gardens. It produces small, inconspicuous green flowers on terminal spikes. You might recognize it as a weed in many warmer regions of the world.

At a glance

Care level: Easy
Plant type: annual herb
Light: full sun
Indoor light: Direct sun
Water: Every 2 to 4 days
Mature size: up to 1 meter
Growth rate: Fast
Hardiness: USDA 9 to 12
Bloom time: Summer to autumn

Care

Keep the soil consistently moist to support its rapid growth cycle. Watch for signs of wilting during hot spells, as this plant prefers steady hydration. It thrives best when given plenty of room to spread in full sun.

Watering: Water whenever the top inch of soil feels dry to the touch.
Feeding: Apply a balanced liquid fertilizer once a month during the active growing season.
Pruning: Trim back spent flower spikes to encourage bushier growth and prevent unwanted seed dispersal.
Repotting: Since this is an annual, you typically do not need to repot it, but you can move it to a larger container if you start it indoors.
Soil: well draining loamy soil
Soil pH: 6.0 to 7.5
Temperature: 15 to 35°C
Humidity: 40 to 70%
Drought tolerance: Moderate
Lifespan: Annual, typically 1 season
Deer and rabbits: Moderate

Signs it needs repotting

Roots growing out of drainage holes
Stunted growth
Soil drying out too quickly

Safety

People: The plant is generally safe to eat when cooked, but raw leaves contain oxalates that may be harmful in large amounts.
Children: The plant is not inherently dangerous, but children should be supervised to prevent accidental ingestion of raw foliage.
Contact allergens: Some individuals may experience mild skin irritation from handling the stems.
Airborne allergens: The pollen can trigger seasonal allergies in sensitive individuals.
Edibility: Ensure plants are harvested from clean soil as they can accumulate heavy metals or nitrates.

How to identify it

ovate leaves with wavy margins
slender green flower spikes
small dark brown seeds
smooth stems without spines

Height: 0.2 to 0.8m
Spread: 0.15 to 0.4m
Leaves: green, deciduous
Flowers: green, 0.1 to 0.3cm
Fruit: brown, Autumn

Problems to watch for

Aphids · Small insects that cluster on new growth and suck plant sap.
Leaf spot · Fungal infections causing discolored patches on leaves.

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: spring
Overwintering: This plant is an annual and will die back after the first frost, so collect seeds for next year.
In containers: It grows well in containers at least 30 cm deep.

Direct Sowing

1. Prepare a sunny spot with loose soil.
2. Sprinkle seeds on the surface.
3. Lightly cover with soil.
4. Keep moist until germination.

Give this plant plenty of space as it can grow quickly and outcompete smaller vegetables.

Grows well with

Tomato · They share similar soil and water requirements in warm climates.
Pepper · They grow well together in sunny garden beds.

Similar species

Redroot Pigweed · It is a related species with a similar growth habit.

Science

Family: Amaranthaceae
Genus: Amaranthus
Order: Caryophyllales
Class: Magnoliopsida
Native range: Tropical and subtropical regions worldwide.
Conservation: This species is widely distributed and considered a common weed, so it is not of conservation concern.

It is a pioneer species that quickly colonizes disturbed ground and open sunny areas.

Value to wildlife: seeds provide food for birds
Pollinators: bees, beetles
Uses: edible greens, traditional medicine, fodder

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 8/9
Temperature: 8/9
Moisture: 5/9
Nutrients: 7/9

Taxonomy resolved against GBIF.

Questions people ask

Is it a weed?: Yes, it is often considered a weed in gardens, though it is also a valued food source.
How do I cook it?: It is typically boiled or stir fried like spinach.

Where the name comes from

The genus name comes from the Greek word amarantos, meaning unfading, while viridis is Latin for green.

Good to know

It is often called slender amaranth.
The seeds are tiny and produced in large quantities.
It thrives in disturbed soils and garden beds.
It is a close relative of the ornamental amaranth.

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This guide was generated with AI on October 24, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.